The Evolution and Implementation of Workload Algorithms in IPME

This report documents a study to validate predictive workload models that are available within the Integrated Performance Modeling Environment (IPME). A literature review was conducted to assess the current state of knowledge of human workload and information processing, as well as to provide a review of the five IPME workload algorithms (VACP, W/Index, IP/PCT, POP, and POPIP). The results of the literature review indicated that, while the theories associated with human information processing are relatively mature, the predictive models of human workload integrated within IPME still require validation against human performance data. Analytical and empirical studies were then conducted within a combined Air Traffic Control (ATC) and Visual Bakan dual-task paradigm. The POP and POPIP analytical models more accurately predicted human subjective workload than did VACP and IP. The IP and POPIP analytical models predicted human performance in the Visual Bakan more accurately than did VACP and POP. All models were equally inaccurate in predicting ATC performance. Theoretical accounts of findings and practical implications for model development are discussed.